1. Field of the Invention
The present invention relates to a circuit having a voltage regulator for providing a supply voltage for at least one first digital subcircuit and a second digital subcircuit, as well as a method for operating a circuit, and a use of a voltage regulator of a first switch and a second switch of a circuit.
2. Description of the Background Art
A circuit of a radio system, particularly according to the industry standard ZigBee, can be supplied by a battery. ZigBee is provided for use of maintenance-free radio switches and radio sensors with a battery supply in poorly or rarely accessible areas. A voltage regulator may be used to generate the necessary supply voltage for digital subcircuits, such as, for example, a memory or signal processing, from the battery voltage of the battery.
U.S. Pat. Application No. 2004/0263237 A1 discloses a semiconductor integrated circuit having a transistor with a non-abrupt switching response for a sleep mode (sleep). A switching mechanism reduces the amplitude of voltage variations in the supply voltage lines and reduces the time interval for stabilizing the supply voltage.
U.S. Publication No. 2005/0068059 A1 discloses a semiconductor integrated circuit with a switching device between a logic circuit and a voltage supply. To output a supply voltage, a voltage regulator is connected to a logic circuit via a PMOS transistor. The voltage regulator is connected to a control circuit to control the voltage regulator, whereby to output a control signal the control circuit is connected to a gate of the PMOS transistor.
A circuit with a voltage supply is disclosed in U.S. Pat. No. 7,098,689 B1, which is connected to a first programmable logic block via a first PMOS transistor and to a second programmable logic block via a second PMOS transistor.